mmc: sdhci-msm: Affine irq to first set of mask when CONFIG_SMP enabled

For MDM targets with single CPU, CONFIG_SMP won't be enabled so
irq_set_affinity_hint will always return EINVAL leading to unnecessary
WARN_ON.

Use irq_set_affinity_hint only for multiple CPU's or when CONFIG_SMP
enabled.

Change-Id: Id37299759927953e485850fb015a3739fd3daed7
Signed-off-by: Sarthak Garg <sartgarg@codeaurora.org>